The present invention concerns rotary conveyors and more specifically relates to arrangements for controlling intake fingers of the conveyor by controlling the position of an eccentric part of a crankshaft on which the fingers are mounted relative to the axis of rotation of a drum having openings slidably receiving the fingers.
EP-A1-0 567 192 reveals an undershot auger conveyor of a harvesting machine including a rotating drum having a horizontal axis of rotation and to which is attached helical vanes and within which is located an intake finger assembly. The intake finger assembly includes a crankshaft whose eccentric central region is designed to pivotally support the intake fingers. Provided in the wall of the central region of the drum are openings respectively aligned with an slidably receiving the fingers of the intake finger assembly. The drum is driven in order to convey crop and as it rotates the intake fingers are carried along by the wall in the circumferential direction and are thereby caused to pivot about their respective connections with the central region of the crankshaft, but the crankshaft itself is retained in a fixed location by flanges. Accordingly the intake fingers extended between a completely retracted position and a fully extended position during a rotation of the drum, so that they can safely grasp crop on the one side of and can safely release it on the other side of the drum. Although the crankshaft is fixed against rotation, it can nevertheless be pivoted within certain limits and retained at another location, if the flanges are released and rotated into another position. In this way the conveying performance of the intake fingers can be changed. It is known in the art to reposition the intake fingers by using a remotely controlled electric motor. In case the rotation of the drum is reversed, the intake fingers are adjusted in such a way that they work in a reverse mode to remove the crop from a further conveyor, normally downstream of the rotary conveyor, and do not add any new crop.
This sort of intake finger control has the disadvantage that it requires an electric or hydraulic motor and plug-in connections at the interface between the harvesting machine and the crop gathering attachment that includes the rotary conveyor, which leads to high costs.